@@ -64,6 +64,7 @@ GNU tar 1.28 tar --version
gtags (optional) 6.6.5 gtags --version
mkimage (optional) 2017.01 mkimage --version
Python (optional) 3.5.x python3 --version
+GNU AWK (optional) 5.1.0 gawk --version
====================== =============== ========================================
.. [#f1] Sphinx is needed only to build the Kernel documentation
@@ -192,6 +193,12 @@ platforms. The tool is available via the ``u-boot-tools`` package or can be
built from the U-Boot source code. See the instructions at
https://docs.u-boot.org/en/latest/build/tools.html#building-tools-for-linux
+GNU AWK
+-------
+
+GNU AWK is needed if you want kernel builds to generate address range data for
+builtin modules (CONFIG_BUILTIN_MODULE_RANGES).
+
System utilities
****************
@@ -571,6 +571,21 @@ config VMLINUX_MAP
pieces of code get eliminated with
CONFIG_LD_DEAD_CODE_DATA_ELIMINATION.
+config BUILTIN_MODULE_RANGES
+ bool "Generate address range information for builtin modules"
+ depends on !LTO
+ depends on VMLINUX_MAP
+ help
+ When modules are built into the kernel, there will be no module name
+ associated with its symbols in /proc/kallsyms. Tracers may want to
+ identify symbols by module name and symbol name regardless of whether
+ the module is configured as loadable or not.
+
+ This option generates modules.builtin.ranges in the build tree with
+ offset ranges (per ELF section) for the module(s) they belong to.
+ It also records an anchor symbol to determine the load address of the
+ section.
+
config DEBUG_FORCE_WEAK_PER_CPU
bool "Force weak per-cpu definitions"
depends on DEBUG_KERNEL
@@ -33,6 +33,24 @@ targets += vmlinux
vmlinux: scripts/link-vmlinux.sh vmlinux.o $(KBUILD_LDS) FORCE
+$(call if_changed_dep,link_vmlinux)
+# module.builtin.ranges
+# ---------------------------------------------------------------------------
+ifdef CONFIG_BUILTIN_MODULE_RANGES
+__default: modules.builtin.ranges
+
+quiet_cmd_modules_builtin_ranges = GEN $@
+ cmd_modules_builtin_ranges = $(real-prereqs) > $@
+
+targets += modules.builtin.ranges
+modules.builtin.ranges: $(srctree)/scripts/generate_builtin_ranges.awk \
+ modules.builtin vmlinux.map vmlinux.o.map FORCE
+ $(call if_changed,modules_builtin_ranges)
+
+vmlinux.map: vmlinux
+ @:
+
+endif
+
# Add FORCE to the prequisites of a target to force it to be always rebuilt.
# ---------------------------------------------------------------------------
@@ -45,9 +45,12 @@ objtool-args = $(vmlinux-objtool-args-y) --link
# Link of vmlinux.o used for section mismatch analysis
# ---------------------------------------------------------------------------
+vmlinux-o-ld-args-$(CONFIG_BUILTIN_MODULE_RANGES) += -Map=$@.map
+
quiet_cmd_ld_vmlinux.o = LD $@
cmd_ld_vmlinux.o = \
$(LD) ${KBUILD_LDFLAGS} -r -o $@ \
+ $(vmlinux-o-ld-args-y) \
$(addprefix -T , $(initcalls-lds)) \
--whole-archive vmlinux.a --no-whole-archive \
--start-group $(KBUILD_VMLINUX_LIBS) --end-group \
new file mode 100755
@@ -0,0 +1,505 @@
+#!/usr/bin/gawk -f
+# SPDX-License-Identifier: GPL-2.0
+# generate_builtin_ranges.awk: Generate address range data for builtin modules
+# Written by Kris Van Hees <kris.van.hees@oracle.com>
+#
+# Usage: generate_builtin_ranges.awk modules.builtin vmlinux.map \
+# vmlinux.o.map > modules.builtin.ranges
+#
+
+# Return the module name(s) (if any) associated with the given object.
+#
+# If we have seen this object before, return information from the cache.
+# Otherwise, retrieve it from the corresponding .cmd file.
+#
+function get_module_info(fn, mod, obj, s) {
+ if (fn in omod)
+ return omod[fn];
+
+ if (match(fn, /\/[^/]+$/) == 0)
+ return "";
+
+ obj = fn;
+ mod = "";
+ fn = substr(fn, 1, RSTART) "." substr(fn, RSTART + 1) ".cmd";
+ if (getline s <fn == 1) {
+ if (match(s, /DKBUILD_MODFILE=['"]+[^'"]+/) > 0) {
+ mod = substr(s, RSTART + 16, RLENGTH - 16);
+ gsub(/['"]/, "", mod);
+ }
+ }
+ close(fn);
+
+ # A single module (common case) also reflects objects that are not part
+ # of a module. Some of those objects have names that are also a module
+ # name (e.g. core). We check the associated module file name, and if
+ # they do not match, the object is not part of a module.
+ if (mod !~ / /) {
+ if (!(mod in mods))
+ mod = "";
+ }
+
+ gsub(/([^/ ]*\/)+/, "", mod);
+ gsub(/-/, "_", mod);
+
+ # At this point, mod is a single (valid) module name, or a list of
+ # module names (that do not need validation).
+ omod[obj] = mod;
+
+ return mod;
+}
+
+# Update the ranges entry for the given module 'mod' in section 'osect'.
+#
+# We use a modified absolute start address (soff + base) as index because we
+# may need to insert an anchor record later that must be at the start of the
+# section data, and the first module may very well start at the same address.
+# So, we use (addr << 1) + 1 to allow a possible anchor record to be placed at
+# (addr << 1). This is safe because the index is only used to sort the entries
+# before writing them out.
+#
+function update_entry(osect, mod, soff, eoff, sect, idx) {
+ sect = sect_in[osect];
+ idx = (soff + sect_base[osect]) * 2 + 1;
+ entries[idx] = sprintf("%s %08x-%08x %s", sect, soff, eoff, mod);
+ count[sect]++;
+}
+
+# (1) Build a lookup map of built-in module names.
+#
+# The first file argument is used as input (modules.builtin).
+#
+# Lines will be like:
+# kernel/crypto/lzo-rle.ko
+# and we record the object name "crypto/lzo-rle".
+#
+ARGIND == 1 {
+ sub(/kernel\//, ""); # strip off "kernel/" prefix
+ sub(/\.ko$/, ""); # strip off .ko suffix
+
+ mods[$1] = 1;
+ next;
+}
+
+# (2) Collect address information for each section.
+#
+# The second file argument is used as input (vmlinux.map).
+#
+# We collect the base address of the section in order to convert all addresses
+# in the section into offset values.
+#
+# We collect the address of the anchor (or first symbol in the section if there
+# is no explicit anchor) to allow users of the range data to calculate address
+# ranges based on the actual load address of the section in the running kernel.
+#
+# We collect the start address of any sub-section (section included in the top
+# level section being processed). This is needed when the final linking was
+# done using vmlinux.a because then the list of objects contained in each
+# section is to be obtained from vmlinux.o.map. The offset of the sub-section
+# is recorded here, to be used as an addend when processing vmlinux.o.map
+# later.
+#
+
+# Both GNU ld and LLVM lld linker map format are supported by converting LLVM
+# lld linker map records into equivalent GNU ld linker map records.
+#
+# The first record of the vmlinux.map file provides enough information to know
+# which format we are dealing with.
+#
+ARGIND == 2 && FNR == 1 && NF == 7 && $1 == "VMA" && $7 == "Symbol" {
+ map_is_lld = 1;
+ if (dbg)
+ printf "NOTE: %s uses LLVM lld linker map format\n", FILENAME >"/dev/stderr";
+ next;
+}
+
+# (LLD) Convert a section record fronm lld format to ld format.
+#
+# lld: ffffffff82c00000 2c00000 2493c0 8192 .data
+# ->
+# ld: .data 0xffffffff82c00000 0x2493c0 load address 0x0000000002c00000
+#
+ARGIND == 2 && map_is_lld && NF == 5 && /[0-9] [^ ]+$/ {
+ $0 = $5 " 0x"$1 " 0x"$3 " load address 0x"$2;
+}
+
+# (LLD) Convert an anchor record from lld format to ld format.
+#
+# lld: ffffffff81000000 1000000 0 1 _text = .
+# ->
+# ld: 0xffffffff81000000 _text = .
+#
+ARGIND == 2 && map_is_lld && !anchor && NF == 7 && raw_addr == "0x"$1 && $6 == "=" && $7 == "." {
+ $0 = " 0x"$1 " " $5 " = .";
+}
+
+# (LLD) Convert an object record from lld format to ld format.
+#
+# lld: 11480 11480 1f07 16 vmlinux.a(arch/x86/events/amd/uncore.o):(.text)
+# ->
+# ld: .text 0x0000000000011480 0x1f07 arch/x86/events/amd/uncore.o
+#
+ARGIND == 2 && map_is_lld && NF == 5 && $5 ~ /:\(/ {
+ gsub(/\)/, "");
+ sub(/ vmlinux\.a\(/, " ");
+ sub(/:\(/, " ");
+ $0 = " "$6 " 0x"$1 " 0x"$3 " " $5;
+}
+
+# (LLD) Convert a symbol record from lld format to ld format.
+#
+# We only care about these while processing a section for which no anchor has
+# been determined yet.
+#
+# lld: ffffffff82a859a4 2a859a4 0 1 btf_ksym_iter_id
+# ->
+# ld: 0xffffffff82a859a4 btf_ksym_iter_id
+#
+ARGIND == 2 && map_is_lld && sect && !anchor && NF == 5 && $5 ~ /^[_A-Za-z][_A-Za-z0-9]*$/ {
+ $0 = " 0x"$1 " " $5;
+}
+
+# (LLD) We do not need any other ldd linker map records.
+#
+ARGIND == 2 && map_is_lld && /^[0-9a-f]{16} / {
+ next;
+}
+
+# (LD) Section records with just the section name at the start of the line
+# need to have the next line pulled in to determine whether it is a
+# loadable section. If it is, the next line will contains a hex value
+# as first and second items.
+#
+ARGIND == 2 && !map_is_lld && NF == 1 && /^[^ ]/ {
+ s = $0;
+ getline;
+ if ($1 !~ /^0x/ || $2 !~ /^0x/)
+ next;
+
+ $0 = s " " $0;
+}
+
+# (LD) Object records with just the section name denote records with a long
+# section name for which the remainder of the record can be found on the
+# next line.
+#
+# (This is also needed for vmlinux.o.map, when used.)
+#
+ARGIND >= 2 && !map_is_lld && NF == 1 && /^ [^ \*]/ {
+ s = $0;
+ getline;
+ $0 = s " " $0;
+}
+
+# Beginning a new section - done with the previous one (if any).
+#
+ARGIND == 2 && /^[^ ]/ {
+ sect = 0;
+}
+
+# Process a loadable section (we only care about .-sections).
+#
+# Record the section name and its base address.
+# We also record the raw (non-stripped) address of the section because it can
+# be used to identify an anchor record.
+#
+# Note:
+# Since some AWK implementations cannot handle large integers, we strip off the
+# first 4 hex digits from the address. This is safe because the kernel space
+# is not large enough for addresses to extend into those digits. The portion
+# to strip off is stored in addr_prefix as a regexp, so further clauses can
+# perform a simple substitution to do the address stripping.
+#
+ARGIND == 2 && /^\./ {
+ # Explicitly ignore a few sections that are not relevant here.
+ if ($1 ~ /^\.orc_/ || $1 ~ /_sites$/ || $1 ~ /\.percpu/)
+ next;
+
+ # Sections with a 0-address can be ignored as well.
+ if ($2 ~ /^0x0+$/)
+ next;
+
+ raw_addr = $2;
+ addr_prefix = "^" substr($2, 1, 6);
+ base = $2;
+ sub(addr_prefix, "0x", base);
+ base = strtonum(base);
+ sect = $1;
+ anchor = 0;
+ sect_base[sect] = base;
+ sect_size[sect] = strtonum($3);
+
+ if (dbg)
+ printf "[%s] BASE %016x\n", sect, base >"/dev/stderr";
+
+ next;
+}
+
+# If we are not in a section we care about, we ignore the record.
+#
+ARGIND == 2 && !sect {
+ next;
+}
+
+# Record the first anchor symbol for the current section.
+#
+# An anchor record for the section bears the same raw address as the section
+# record.
+#
+ARGIND == 2 && !anchor && NF == 4 && raw_addr == $1 && $3 == "=" && $4 == "." {
+ anchor = sprintf("%s %08x-%08x = %s", sect, 0, 0, $2);
+ sect_anchor[sect] = anchor;
+
+ if (dbg)
+ printf "[%s] ANCHOR %016x = %s (.)\n", sect, 0, $2 >"/dev/stderr";
+
+ next;
+}
+
+# If no anchor record was found for the current section, use the first symbol
+# in the section as anchor.
+#
+ARGIND == 2 && !anchor && NF == 2 && $1 ~ /^0x/ && $2 !~ /^0x/ {
+ addr = $1;
+ sub(addr_prefix, "0x", addr);
+ addr = strtonum(addr) - base;
+ anchor = sprintf("%s %08x-%08x = %s", sect, addr, addr, $2);
+ sect_anchor[sect] = anchor;
+
+ if (dbg)
+ printf "[%s] ANCHOR %016x = %s\n", sect, addr, $2 >"/dev/stderr";
+
+ next;
+}
+
+# The first occurence of a section name in an object record establishes the
+# addend (often 0) for that section. This information is needed to handle
+# sections that get combined in the final linking of vmlinux (e.g. .head.text
+# getting included at the start of .text).
+#
+# If the section does not have a base yet, use the base of the encapsulating
+# section.
+#
+ARGIND == 2 && sect && NF == 4 && /^ [^ \*]/ && !($1 in sect_addend) {
+ if (!($1 in sect_base)) {
+ sect_base[$1] = base;
+
+ if (dbg)
+ printf "[%s] BASE %016x\n", $1, base >"/dev/stderr";
+ }
+
+ addr = $2;
+ sub(addr_prefix, "0x", addr);
+ addr = strtonum(addr);
+ sect_addend[$1] = addr - sect_base[$1];
+ sect_in[$1] = sect;
+
+ if (dbg)
+ printf "[%s] ADDEND %016x - %016x = %016x\n", $1, addr, base, sect_addend[$1] >"/dev/stderr";
+
+ # If the object is vmlinux.o then we will need vmlinux.o.map to get the
+ # actual offsets of objects.
+ if ($4 == "vmlinux.o")
+ need_o_map = 1;
+}
+
+# (3) Collect offset ranges (relative to the section base address) for built-in
+# modules.
+#
+# If the final link was done using the actual objects, vmlinux.map contains all
+# the information we need (see section (3a)).
+# If linking was done using vmlinux.a as intermediary, we will need to process
+# vmlinux.o.map (see section (3b)).
+
+# (3a) Determine offset range info using vmlinux.map.
+#
+# Since we are already processing vmlinux.map, the top level section that is
+# being processed is already known. If we do not have a base address for it,
+# we do not need to process records for it.
+#
+# Given the object name, we determine the module(s) (if any) that the current
+# object is associated with.
+#
+# If we were already processing objects for a (list of) module(s):
+# - If the current object belongs to the same module(s), update the range data
+# to include the current object.
+# - Otherwise, ensure that the end offset of the range is valid.
+#
+# If the current object does not belong to a built-in module, ignore it.
+#
+# If it does, we add a new built-in module offset range record.
+#
+ARGIND == 2 && !need_o_map && /^ [^ ]/ && NF == 4 && $3 != "0x0" {
+ if (!(sect in sect_base))
+ next;
+
+ # Turn the address into an offset from the section base.
+ soff = $2;
+ sub(addr_prefix, "0x", soff);
+ soff = strtonum(soff) - sect_base[sect];
+ eoff = soff + strtonum($3);
+
+ # Determine which (if any) built-in modules the object belongs to.
+ mod = get_module_info($4);
+
+ # If we are processing a built-in module:
+ # - If the current object is within the same module, we update its
+ # entry by extending the range and move on
+ # - Otherwise:
+ # + If we are still processing within the same main section, we
+ # validate the end offset against the start offset of the
+ # current object (e.g. .rodata.str1.[18] objects are often
+ # listed with an incorrect size in the linker map)
+ # + Otherwise, we validate the end offset against the section
+ # size
+ if (mod_name) {
+ if (mod == mod_name) {
+ mod_eoff = eoff;
+ update_entry(mod_sect, mod_name, mod_soff, eoff);
+
+ next;
+ } else if (sect == sect_in[mod_sect]) {
+ if (mod_eoff > soff)
+ update_entry(mod_sect, mod_name, mod_soff, soff);
+ } else {
+ v = sect_size[sect_in[mod_sect]];
+ if (mod_eoff > v)
+ update_entry(mod_sect, mod_name, mod_soff, v);
+ }
+ }
+
+ mod_name = mod;
+
+ # If we encountered an object that is not part of a built-in module, we
+ # do not need to record any data.
+ if (!mod)
+ next;
+
+ # At this point, we encountered the start of a new built-in module.
+ mod_name = mod;
+ mod_soff = soff;
+ mod_eoff = eoff;
+ mod_sect = $1;
+ update_entry($1, mod, soff, mod_eoff);
+
+ next;
+}
+
+# If we do not need to parse the vmlinux.o.map file, we are done.
+#
+ARGIND == 3 && !need_o_map {
+ if (dbg)
+ printf "Note: %s is not needed.\n", FILENAME >"/dev/stderr";
+ exit;
+}
+
+# (3) Collect offset ranges (relative to the section base address) for built-in
+# modules.
+#
+
+# (LLD) Convert an object record from lld format to ld format.
+#
+ARGIND == 3 && map_is_lld && NF == 5 && $5 ~ /:\(/ {
+ gsub(/\)/, "");
+ sub(/:\(/, " ");
+
+ sect = $6;
+ if (!(sect in sect_addend))
+ next;
+
+ sub(/ vmlinux\.a\(/, " ");
+ $0 = " "sect " 0x"$1 " 0x"$3 " " $5;
+}
+
+# (3b) Determine offset range info using vmlinux.o.map.
+#
+# If we do not know an addend for the object's section, we are interested in
+# anything within that section.
+#
+# Determine the top-level section that the object's section was included in
+# during the final link. This is the section name offset range data will be
+# associated with for this object.
+#
+# The remainder of the processing of the current object record follows the
+# procedure outlined in (3a).
+#
+ARGIND == 3 && /^ [^ ]/ && NF == 4 && $3 != "0x0" {
+ osect = $1;
+ if (!(osect in sect_addend))
+ next;
+
+ # We need to work with the main section.
+ sect = sect_in[osect];
+
+ # Turn the address into an offset from the section base.
+ soff = $2;
+ sub(addr_prefix, "0x", soff);
+ soff = strtonum(soff) + sect_addend[osect];
+ eoff = soff + strtonum($3);
+
+ # Determine which (if any) built-in modules the object belongs to.
+ mod = get_module_info($4);
+
+ # If we are processing a built-in module:
+ # - If the current object is within the same module, we update its
+ # entry by extending the range and move on
+ # - Otherwise:
+ # + If we are still processing within the same main section, we
+ # validate the end offset against the start offset of the
+ # current object (e.g. .rodata.str1.[18] objects are often
+ # listed with an incorrect size in the linker map)
+ # + Otherwise, we validate the end offset against the section
+ # size
+ if (mod_name) {
+ if (mod == mod_name) {
+ mod_eoff = eoff;
+ update_entry(mod_sect, mod_name, mod_soff, eoff);
+
+ next;
+ } else if (sect == sect_in[mod_sect]) {
+ if (mod_eoff > soff)
+ update_entry(mod_sect, mod_name, mod_soff, soff);
+ } else {
+ v = sect_size[sect_in[mod_sect]];
+ if (mod_eoff > v)
+ update_entry(mod_sect, mod_name, mod_soff, v);
+ }
+ }
+
+ mod_name = mod;
+
+ # If we encountered an object that is not part of a built-in module, we
+ # do not need to record any data.
+ if (!mod)
+ next;
+
+ # At this point, we encountered the start of a new built-in module.
+ mod_name = mod;
+ mod_soff = soff;
+ mod_eoff = eoff;
+ mod_sect = osect;
+ update_entry(osect, mod, soff, mod_eoff);
+
+ next;
+}
+
+# (4) Generate the output.
+#
+# Anchor records are added for each section that contains offset range data
+# records. They are added at an adjusted section base address (base << 1) to
+# ensure they come first in the second records (see update_entry() above for
+# more informtion).
+#
+# All entries are sorted by (adjusted) address to ensure that the output can be
+# parsed in strict ascending address order.
+#
+END {
+ for (sect in count) {
+ if (sect in sect_anchor)
+ entries[sect_base[sect] * 2] = sect_anchor[sect];
+ }
+
+ n = asorti(entries, indices);
+ for (i = 1; i <= n; i++)
+ print entries[indices[i]];
+}